Know your premium hands.

What is the strongest starting hand in Texas Hold’em?

Knowing premium hands is important, but I think the harder lesson is knowing when not to fall in love with them. AA or KK can still become very uncomfortable once the board and action start telling a different story.

Undoubtedly, the strongest starting hand in poker is the pair AA.

Pocket AA allows you to "step on the gas" already on the first betting round. Aces are almost always willing to go for stack preflop.AK and AQ will bring a good profit if they hit top pair. Many opponents are unfamiliar with the concept of "dominance" and are willing to pay two or three streets with aces, kings, or queens. It's hard for a beginner to give up when they hit top pair of aces. The kicker becomes secondary for them.

If you play the tour online, AA still loses as usual. I've lost to AA before. Even small hands can get beaten by bigger small hands.